Image processing apparatus

ABSTRACT

When an acquired image file GF includes image processing control information GI, a CPU executes image quality adjustment of image data GD in an image processing mode GM specified by the image processing control information GI. When the acquired image file GF does not include the image processing control information GI, on the other hand, the CPU retrieves Exif information and in the case of successful retrieval of the Exif information, selects the image processing mode GM based on the Exif information and executes image quality adjustment of the image data GD in the selected image processing mode GM. In the case where a selected shooting mode is described in the Exif information, the selected shooting mode is used for the selection of the image processing mode GM. In the case where no selected shooting mode is described in the Exif information, on the other hand, another shooting condition is used for the selection of the image processing mode GM.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. application Ser. No.10/634,741, filed on Aug. 4, 2003. The disclosure of this priorapplication from which priority is claimed is incorporated herein byreference.

FIELD OF TECHNOLOGY

The present invention relates to an image processing technique that usesshooting information or information on specification of image processingto implement the image processing of image data.

BACKGROUND OF THE INVENTION

Digital still cameras (DSC) having shooting modes corresponding tovarious shooting scenes, such as portrait and nightscape have beenwidely used. In response to selection of a shooting mode, the DSC is setto have preset values of multiple shooting parameters, such as shutterspeed and exposure, corresponding to the selected shooting mode. Thephotographer is thus not required to individually set the shootingparameters and easily takes photographs of a subject under shootingconditions specified by the selected shooting mode. In the case of imagedata complying with a DSC file format standard Exif 2.2, the selectedshooting mode is written, together with other shooting conditionsincluding a shutter speed, an exposure mode, and a light source, in aheader or an equivalent portion of the image data.

The applicant of the invention has proposed a practical technique thatsets image processing control information for specifying imageprocessing conditions adopted in an image processing apparatus accordingto the shooting mode selected in the DSC, the shooting conditions, andthe reproduction characteristics of an output device, and outputs thesettings of the image processing control information related to imagedata. This technique ensures image processing suitable for the shootingmode selected by the photographer (that is, image processing reflectingthe intention of the photographer). The image processing controlinformation used in this technique is set by taking into account thereproduction characteristics of the output device and is thussubstantially different from the shooting information, which simplydescribes the shooting conditions.

The shooting information including the shooting mode is, however,included in a greater number of image data (image files), compared withthe image processing control information. When the image processingcontrol information is not available, it is desirable to utilize theshooting information and thereby make a greater number of image datasubjected to image processing suitable for a shooting scene at the timeof shooting (that is, a shooting mode selected by the photographer).

SUMMARY OF THE INVENTION

In order to solve the above problems of the prior art technique, thepresent invention aims to make a greater number of, image data subjectedto a series of image processing suitable for a shooting scene at a timeof shooting each of the image data.

A first application of the invention to attain the above object isdirected to an image processing method that makes image data, whichincludes shooting information obtained at a time of shooting, subjectedto a series of image processing suitable for a selected shooting scene.The image processing method in the first application of the inventionacquires image data; retrieves scene-dependent image processingcondition specification information, which is related to the acquiredimage data and is used to specify a scene-dependent image processingcondition suitable for the selected shooting scene; specifies theselected shooting scene based on the shooting information, in the caseof failed retrieval of the scene-dependent image processing conditionspecification information; acquires a scene-dependent image processingcondition suitable for the specified shooting scene from a memorydevice, which stores multiple scene-dependent image processingconditions set for multiple shooting scenes; and executes image qualityadjustment of the image data with the acquired scene-dependent imageprocessing condition.

In accordance with the first application of the invention, even when thescene-dependent image processing condition specification information,which is used to specify the scene-dependent image processing conditionsuitable for the selected shooting scene, is not available, the imageprocessing method in the first application of the invention utilizes thegeneral shooting information given as attribute information of the imagedata to obtain the scene-dependent image processing condition suitablefor the selected shooting scene and executes image quality adjustmentwith the obtained scene-dependent image processing condition. Thisarrangement desirably enables a greater number of image data to besubjected to the image processing suitable for the shooting scene at thetime of shooting each of the image data.

In the first application of the invention, in the case of successfulretrieval of the scene-dependent image processing conditionspecification information, the image processing method may acquire thescene-dependent image processing condition corresponding to theretrieved scene-dependent image processing condition specificationinformation from the memory device. In this arrangement, thescene-dependent image processing condition may be is acquired, based onthe scene-dependent image processing condition specification informationrepresenting the photographer's intention at the time of shooting, thusensuring execution of image quality adjustment reflecting the intentionof the photographer.

In another preferable arrangement of the first application of theinvention, when the shooting information includes preset information ofshooting scene, the image processing method may specify the shootingscene, based on the preset information of shooting scene. In thisarrangement, the preset information of shooting scene at the time ofshooting is utilized to acquire the scene-dependent image processingcondition, which reflects the shooting scene, and thereby ensuresexecution of image quality adjustment suitable for the shooting scene.

In the image processing method according to the first application of theinvention, one preferable procedure specifies the shooting scene, basedon information on settings of exposure program, aperture, shutter speed,subject distance range, ISO speed rate, and flash included in theshooting information. These pieces of the shooting information may beused for estimation of the shooting scene.

In the image processing method according to the first application of theinvention, when the shooting information does not include the presetinformation of shooting scene, the shooting scene may be specified,based on information on settings of exposure program, aperture, shutterspeed, subject distance range, ISO speed rate, and flash included in theshooting information. This arrangement ensures execution of imagequality adjustment suitable for the shooting scene, even when theinformation of shooting scene is not available.

In the image processing method according to the first application of theinvention, the scene-dependent image processing condition may be acombination of values of multiple image quality-relating parameters,which are set in advance for each shooting scene. This arrangementensures adaptation of image quality adjustment for the shooting scenewith a high accuracy.

The first application of the invention is also actualized by an imageprocessing apparatus that makes image data, which includes shootinginformation obtained at a time of shooting, subjected to a series ofimage processing suitable for a selected shooting scene. The imageprocessing apparatus in the first application of the invention includes:an image data acquisition module that acquires image data; a memorymodule that stores multiple scene-dependent image processing conditionsset for multiple shooting scenes; a scene-dependent image processingcondition acquisition module that, in the case of failed retrieval ofscene-dependent image processing condition specification information,which is related to the acquired image data and is used to specify ascene-dependent image processing condition suitable for the selectedshooting scene, specifies the selected shooting scene based on theshooting information and acquires a scene-dependent image processingcondition suitable for the specified shooting scene from the memorymodule; and an image quality adjustment module that executes imagequality adjustment of the image data with the acquired scene-dependentimage processing condition.

The image processing apparatus according to the first application of theinvention has similar functions and effects to those of the imageprocessing method in the first application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

The first application of the invention is further actualized by acomputer program product storing a program that causes a computer toutilize multiple scene-dependent image processing conditions set formultiple shooting scenes and to make image data, which includes shootinginformation obtained at a time of shooting, subjected to a series ofimage processing suitable for a selected shooting scene. In the computerprogram product according to the first application of the invention, theprogram includes: a computer command that retrieves scene-dependentimage processing condition specification information, which is relatedto acquired image data and is used to specify a scene-dependent imageprocessing condition suitable for the selected shooting scene; acomputer command that specifies the selected shooting scene based on theshooting information, in the case of failed retrieval of thescene-dependent image processing condition specification information; acomputer command that selects a scene-dependent image processingcondition suitable for the specified shooting scene among the multiplescene-dependent image processing conditions; and a computer command thatexecutes image quality adjustment of the image data with the selectedscene-dependent image processing condition.

The computer program product according to the first application of theinvention has similar functions and effects to those of the imageprocessing method in the first application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

A second application of the invention is directed to an image processingmethod that executes a series of image processing suitable for ashooting scene selected at a time of shooting. The image processingmethod in the second application of the invention acquires image data;retrieves image processing control information, which specifies ascene-dependent image processing condition suitable for the selectedshooting scene and is related to the acquired image data; in the case ofsuccessful retrieval of the image processing control information,acquired the scene-dependent image processing condition specified by theretrieved image processing control information from a memory device,which stores multiple scene-dependent image processing conditions ascombinations of values of multiple image quality-relating parameters setin advance for multiple shooting scenes; and executes image qualityadjustment of the image data with the acquired scene-dependent imageprocessing condition.

The image processing method in the second application of the inventionutilizes the image processing control information, which is used tospecify the scene-dependent image processing condition suitable for theselected shooting scene, to acquire the scene-dependent image processingcondition suitable for the shooting scene and executes image qualityadjustment with the obtained scene-dependent image processing condition.This arrangement desirably enables the scene-dependent image processingcondition, which represents the photographer's intention at the time ofshooting, to be obtained adequately, thus ensuring execution of imagequality adjustment reflecting the intention of the photographer.

In one preferable arrangement of the second application of theinvention, the image processing method determines the shooting sceneselected at the time of shooting, based on the shooting information. Inthe case of failed retrieval of the image processing controlinformation, the image processing method acquires out thescene-dependent image processing condition suitable for the definitelyset shooting scene from the memory device. In such cases, the procedureof this arrangement utilizes the general shooting information given asattribute information of the image data to acquire the scene-dependentimage processing condition suitable for the shooting scene. Thisdesirably enables a greater number of image data to be subjected toimage quality adjustment suitable for the shooting scene at the time ofshooting each of the image data.

The second application of the invention is also actualized by an imageprocessing apparatus that executes a series of image processing suitablefor a shooting scene selected at a time of shooting. The imageprocessing apparatus in the second application of the inventionincludes: an image data acquisition module that acquires image data; amemory module that stores multiple scene-dependent image processingconditions as combinations of values of multiple image quality-relatingparameters set in advance for multiple shooting scenes; ascene-dependent image processing condition acquisition module that, inthe case of successful retrieval of image processing controlinformation, which specifies a scene-dependent image processingcondition suitable for the selected shooting scene and is related to theacquired image data, acquires the scene-dependent image processingcondition specified by the retrieved image processing controlinformation from the memory module; and an image quality adjustmentmodule that executes image quality adjustment of the image data with theacquired scene-dependent image processing condition.

The image processing apparatus according to the second application ofthe invention has similar functions and effects to those of the imageprocessing method in the second application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

The second application of the invention is further actualized by acomputer program product storing an image processing program that causesa computer to utilize multiple scene-dependent image processingconditions as combinations of values of multiple image quality-relatingparameters set in advance for multiple shooting scenes and to execute aseries of image processing suitable for a shooting scene selected at atime of shooting. In the computer program product according to thesecond application of the invention, the image processing programincludes: a program command that retrieves image processing controlinformation, which specifies a scene-dependent image processingcondition suitable for the selected shooting scene and is related toacquired image data; a program command that, in the case of successfulretrieval of the image processing control information, selects thescene-dependent image processing condition specified by the retrievedimage processing control information, among the multiple scene-dependentimage processing conditions; and a program command that executes imagequality adjustment of the image data with the selected scene-dependentimage processing condition.

The computer program product according to the second application of theinvention has similar functions and effects to those of the imageprocessing method in the second application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

A third application of the invention is directed to an image processingmethod that makes image data, which includes shooting informationobtained at a time of shooting, subjected to a series of imageprocessing. The image processing method in the third application of theinvention retrieves image processing control information, which isrelated to the image data and is used to specify an image processingcondition; in the case of failed retrieval of the image processingcontrol information, selects an image processing condition, which issuitable for a shooting condition at the time of shooting, based on theshooting information from a memory device that stores multiple differentimage processing conditions set for the image data; and executes imagequality adjustment of the image data with the selected image processingcondition.

In accordance with the third application of the invention, even when theimage processing control information, which is used to specify the imageprocessing condition, is not available, the image processing method inthe third application of the invention utilizes the general shootinginformation given as attribute information of the image data to acquirethe image processing condition, which corresponds to the image data andis suitable for the shooting condition at the time of shooting, andexecutes image quality adjustment with the obtained image processingcondition. This arrangement desirably enables a greater number of imagedata to be subjected to the image processing suitable for the shootingcondition at the time of shooting each of the image data.

In one preferable arrangement of the third application of the invention,in the case of successful retrieval of the image processing controlinformation, the image processing method selects an image processingcondition specified by the retrieved image processing controlinformation from the memory device. The procedure of this arrangementutilizes the image processing control information to acquire the imageprocessing condition, thus ensuring execution of image qualityadjustment reflecting the intention of the photographer.

In another preferable arrangement of the third application of theinvention, when the shooting information includes preset information ofshooting scene at the time of shooting, the image processing methodselects the image processing condition, based on the preset informationof shooting scene. The procedure of this arrangement utilizes the presetinformation of shooting scene at the time of shooting to acquire theimage processing condition, which reflects the shooting scene, andthereby ensures execution of image quality adjustment suitable for theshooting scene.

In still another preferable arrangement of the third application of theinvention, the image processing method selects the image processingcondition, based on at least information on settings of exposureprogram, aperture, shutter speed, subject distance range, ISO speedrate, and flash included in the shooting information. These pieces ofthe shooting information may be used for estimation of the shootingscene.

When the shooting information does not include the preset information ofshooting scene at the time of shooting, the image processing conditionmay be selected, based on at least information on settings of exposureprogram, aperture, shutter speed, subject distance range, ISO speedrate, and flash included in the shooting information. This arrangementensures execution of image quality adjustment suitable for the shootingscene, even when the information of shooting scene is not available.

In the image processing method according to the third application of theinvention, the image processing condition may be a combination of valuesof multiple image quality-relating parameters, which are set in advancefor each shooting scene. This arrangement ensures adaptation of imagequality adjustment for the shooting scene with a high accuracy.

The third application of the invention is also actualized by an imageprocessing apparatus that makes image data, which includes shootinginformation obtained at a time of shooting, subjected to a series ofimage processing. The image processing apparatus in the thirdapplication of the invention includes: a memory module that storesmultiple different image processing conditions set for the image data; aselection module that, in the case of failed retrieval of imageprocessing control information that is related to the image data and isused to specify an image processing condition, selects an imageprocessing condition, which is suitable for a shooting condition at thetime of shooting, based on the shooting information from the memorymodule; and an image quality adjustment module that executes imagequality adjustment of the image data with the selected image processingcondition.

The image processing apparatus according to the third application of theinvention has similar functions and effects to those of the imageprocessing method in the third application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

The third application of the invention is further actualized by acomputer program product storing an image processing program that causesa computer to make image data, which includes shooting informationobtained at a time of shooting, subjected to a series of imageprocessing. In the computer program product according to the thirdapplication of the invention, the image processing program includes: aprogram command that retrieves image processing control information thatis related to the image data and is used to specify an image processingcondition; a program command that, in the case of failed retrieval ofthe image processing control information, selects an image processingcondition, which is suitable for a shooting condition at the time ofshooting, based on the shooting information among multiple differentimage processing conditions set in advance for the image data; and aprogram command that executes image quality adjustment of the image datawith the selected image processing condition.

The computer program product according to the third application of theinvention has similar functions and effects to those of the imageprocessing method in the third application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

A fourth application of the invention is directed to an image processingmethod that executes image processing of image data having shootinginformation, which is obtained at a time of shooting and includesinformation on a selected shooting scene. The image processing method inthe fourth application of the invention acquires image data; acquires ascene-dependent image processing condition suitable for the selectedshooting scene from a memory device, which stores multiplescene-dependent image processing conditions as image processingconditions suitable for respective shooting scenes; and executes imagequality adjustment of the image data with the acquired scene-dependentimage processing condition.

The image processing method in the fourth application of the inventionobtains the scene-dependent image processing condition suitable for theselected shooting scene and executes image quality adjustment with theacquired scene-dependent image processing condition. This arrangementenables the image data to be subjected to image processing suitable forthe shooting scene at the time of shooting.

In one preferable arrangement of the fourth application of theinvention, the image data is associated with scene-dependent imageprocessing condition specification information, which is used to specifythe scene-dependent image processing condition applied for imageprocessing. The image processing method receives selection informationthat determines which of the selected shooting scene and thescene-dependent image processing scene condition is to be used toacquire the scene-dependent image processing condition, and acquires thescene-dependent image processing condition from the memory device,according to the received selection information.

The procedure of this arrangement acquires the scene-dependent imageprocessing condition, based on either the selected shooting scene or thescene-dependent image processing condition specification information,which is used to specify the scene-dependent image processing conditionapplied for image processing. This arrangement enables the image data tobe subjected to image processing suitable for a desired shooting scenewith desired information.

In the fourth application of the invention, the memory device may storea first scene-dependent image processing condition corresponding to theshooting scene and a second scene-dependent image processing conditioncorresponding to the scene-dependent image processing conditionspecification information. The image processing method may select eitherof the first scene-dependent image processing condition and the secondscene-dependent image processing condition according to the receivedselection information, so as to acquire the scene-dependent imageprocessing condition. This arrangement enables the image data to besubjected to more adequate image processing for a desired shootingscene.

The fourth application of the invention is also actualized by an imageprocessing apparatus that executes image processing of image data havingshooting information, which is obtained at a time of shooting andincludes information on a selected shooting scene. The image processingapparatus in the fourth application of the invention includes: an imagedata acquisition module that acquires image data; a memory module thatstores multiple scene-dependent image processing conditions as imageprocessing conditions suitable for respective shooting scenes; and animage quality adjustment module that acquires a scene-dependent imageprocessing condition suitable for the selected shooting scene from thememory module and executes image quality adjustment of the image datawith the acquired scene-dependent image processing condition.

The image processing apparatus according to the fourth application ofthe invention has similar functions and effects to those of the imageprocessing method in the fourth application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

The fourth application of the invention is further actualized by acomputer program product storing an image processing program that causesa computer to execute image processing of image data having shootinginformation, which is obtained at a time of shooting and includesinformation on a selected shooting scene. In the computer programproduct according to the fourth application of the invention, the imageprocessing program includes: a program code that acquires image data; aprogram code that acquires a scene-dependent image processing conditionsuitable for the selected shooting scene from a memory device, whichstores multiple scene-dependent image processing conditions as imageprocessing conditions suitable for respective shooting scenes; and aprogram code that executes image quality adjustment of the image datawith the acquired scene-dependent image processing condition.

The computer program product according to the fourth application of theinvention has similar functions and effects to those of the imageprocessing method in the fourth application of the invention and hasvarious arrangements as discussed above with regard to the imageprocessing method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an image processing system as one embodiment, to which animage processing apparatus of the invention is applied;

FIG. 2 is a block diagram schematically illustrating the structure of adigital still camera that is usable for generating image files (imagedata);

FIG. 3 shows selection of a shooting mode in the digital still camera;

FIG. 4 is a block diagram schematically illustrating the structure of acolor printer functioning as an image processing apparatus in theembodiment;

FIG. 5 shows the file structure of an Exif image file;

FIG. 6 shows the detailed internal structure of shooting condition tagsin the Exif file format used in the embodiment;

FIG. 7 shows settings of multiple image quality-relating parameters,which are stored in an HDD 152 (or a ROM) of a personal computer PC anddefine options of an image processing mode GM specified by imageprocessing control information GI;

FIG. 8 is a flowchart showing an image processing routine executed by animage processing apparatus (personal computer PC) in the embodiment;

FIG. 9 is a flowchart showing an image quality adjustment routine withthe image processing control information GI executed by the imageprocessing apparatus (personal computer PC) in the embodiment;

FIG. 10 is a flowchart showing an image quality adjustment routine withExif information executed by the image processing apparatus (personalcomputer PC) in the embodiment; and

FIG. 11 shows a table that maps the Exif information to the imageprocessing mode GM.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The image processing apparatus of the invention is discussed below as apreferred embodiment with reference to the accompanied drawings.

A. Construction of Image Processing System

The construction of an image processing system including an imageprocessing apparatus in one embodiment is discussed below with referenceto FIGS. 1 through 4. FIG. 1 shows an image processing system as oneembodiment, to which an image processing apparatus of the invention isapplied. FIG. 2 is a block diagram schematically illustrating thestructure of a digital still camera that is usable for generating imagefiles (image data). FIG. 3 shows selection of a shooting mode in thedigital still camera. FIG. 4 is a block diagram schematicallyillustrating the structure of a color printer functioning as an imageprocessing apparatus in the embodiment.

The image processing system includes a digital still camera 12functioning as an input device to generate an image file, a personalcomputer PC functioning as an image processing apparatus to executeimage processing based on the image file generated by the digital stillcamera 12 and to output print image data, and a color printer 20functioning as an output device to output resulting images according tothe print image data. The color printer 20 may have the image processingfunctions of the personal computer PC. In this case, the color printer20 works as a stand-alone to implement image processing and output ofresulting images. The output device is not restricted to the printer 20but may be a monitor 14 like a CRT display or an LCD display or aprojector. In the description below, the color printer 20 connectingwith the personal computer PC is used as the output device.

The personal computer PC is a general-purpose computer and includes aCPU 150 that executes an image processing program of the invention, aRAM 151 that temporarily stores the results of operations by the CPU 150and image data, and a hard disk drive (HDD) 152 that stores the imageprocessing program. The personal computer PC also has a card slot 153that receives a memory card MC inserted therein and an input outputterminal 154 that connects with a connector cable linked with thedigital still camera 12.

The digital still camera 12 focuses light information on a digitaldevice (for example, a CCD or an electron multiplier tube) to acquire animage, and has an optical circuit 121 including the CCD or the like tocollect the light information, an image acquisition circuit 122 thatcontrols the optical circuit 121 to acquire a digital image, an imageprocessing circuit 123 that processes the acquired digital image, and acontrol circuit 124 that has a memory and controls the respectivecircuits, as shown in FIG. 2. The digital still camera 12 stores theacquired images as digital data into a memory device, such as a memorycard MC. The JPEG data format as an irreversible compression storagesystem and the TIFF data format as a reversible compression storagesystem are typically applied for storage of image data in the digitalstill camera 12. Other storage formats like the RAW data format, the GIFdata format, and the BMP data format are also applicable for storage ofimage data.

As shown in FIG. 3, the digital still camera 12 also has a selection/setbutton 126 and a liquid crystal display 127, which is used to previeweach shot image and effectuate selection and setting through operationsof the selection/set button 126. The selection/set button 126 may beused to set a shooting mode, which specifies shooting conditionsincluding a shutter speed, an exposure program, and an ISO speed rate,as well as values of multiple shooting parameters corresponding to eachshooting scene, such as twilight scene, nightscape, or portrait.

When the digital still camera 12 has the function of specifying a seriesof image processing to be executed by the image processing apparatuswith image processing control information GI, the selection/set button126 may be used to set individual image processing control parameters,such as lightness, contrast, quantity of exposure correction (exposurecorrection value), and white balance, or to set an image processing mode(shooting mode), which specifies values of multiple image processingcontrol parameters used in the image processing apparatus according tothe shooting conditions. The selection/set button 126 may otherwise beused to set both the shooting mode and the image processing mode.

The digital still camera 12 maps image processing control informationGI, which is used to specify image processing of image data executed bythe image processing apparatus (the color printer 20 and the personalcomputer PC), or Exif information, which represents shooting informationat the time of shooting image data, to the image data and stores themapping in the form of an image file GF into the memory card MC. Whenthe user selects a shooting mode (shooting scene), for example,portrait, nightscape, or twilight scene, suitable for shootingconditions, the procedure maps the selected shooting mode as the Exifinformation to the image data or maps an image processing mode, whichcorresponds to the selected shooting mode and specifies values or levelsof multiple image processing control parameters including contrast,saturation, and sharpness, to the image data and stores the mapping intothe memory card MC. The multiple image processing control parameters mayinclude individually settable parameters like the quantity of exposurecorrection and the white balance. The settings of shooting parametersapplied for each shooting mode and image processing parameters arerelated to the shooting mode and are stored on the memory in the controlcircuit 124 of the digital still camera 12.

The image file GF generated by the digital still camera 12 istransmitted to the color printer 20 via a connector cable CV and thecomputer PC or directly via the connector cable CV. The image file GF isotherwise transmitted to the color printer 20 by inserting the memorycard MC, in which the image file GF has been stored by the digital stillcamera 12, into a memory card slot of the computer PC or by directlyconnecting the memory card MC with the printer 20. In the structure ofthe embodiment, the personal computer PC executes image processing ofthe image data with the image processing control information GI andoutputs the processed image data to the color printer 20.

The color printer 20 shown in FIG. 4 is capable of outputting colorimages and is, for example, an ink jet printer that ejects four colorinks, cyan (C), magenta (M), yellow (Y), and black (K), on a printingmedium to create a dot pattern and thereby form an image. Anotherexample of the color printer 20 is an electrophotographic printer thattransfers and fixes color toners on a printing medium to form an image.Other color inks, light cyan (LC), light magenta (LM), and dark yellow(DY) may also be used, in addition to the above four color inks.

As illustrated, the color printer 20 has a mechanism that drives printheads IH1 through IH4 mounted on a carriage 30 to eject inks and createdots, a mechanism that activates a carriage motor 31 to reciprocate thecarriage 30 along a shaft of a platen 32, a mechanism that activates asheet feed motor 33 to feed a cut sheet of printing paper 40, and acontrol circuit 50. The mechanism of reciprocating the carriage 30 alongthe shaft of the platen 32 has a sliding shaft 34 that holds thecarriage 30 arranged in parallel with the shaft of the platen 32 in aslidable manner and a pulley 36 that supports an endless belt 35 spannedbetween the carriage motor 31 and the pulley 36.

The control circuit 50 adequately controls the operations of the sheetfeed motor 33, the carriage motor 31, and the print heads IH1 throughIH4 in response to a print command sent from the personal computer PCand outputs image data sent from the personal computer PC as an image ona printing medium. Ink cartridge INC1 and INC2 are attached to thecarriage 30. The ink cartridge INC1 keeps black (K) ink, whereas the inkcartridge INC2 keeps the other inks, that is, the three color inks, cyan(C), magenta (M), and yellow (Y). Additional inks of light cyan (LC),light magenta (LM), and dark yellow (DY) may also be kept in the inkcartridge, as mentioned previously.

B. Structure of Image File

The image file GF of this embodiment may have, for example, a filestructure in conformity with the Exif format (Exif file) that wasspecified as a standard of the image file format for digital stillcameras by Japan Electronics and Information Technology IndustriesAssociation (JEITA), a file structure in conformity with the JFIF format(JFIF file) that was specified as a standard for making JPEG data filescompatible by three corporations, C-Cube Microsystems, Xing Technology,and Digital Origin (Radius), or a file structure in conformity with theTIFF format (TIFF file) that specifies parameters relating to image datain the form of tags. The Exif files are classified by the type of imagedata stored therein into JPEG-Exif files that store JPEG image data inan irreversible compressed form and TIFF-Exif files that store TIFFimage data in a reversible compressed form.

The general structure of an Exif image file as a JPEG data storage fileused in this embodiment is discussed below with reference to FIGS. 5through 7. FIG. 5 shows the file structure of an Exif image file. FIG. 6shows the detailed internal structure of shooting condition tags in theExif file format used in the embodiment. FIG. 7 shows settings ofmultiple image quality-relating parameters, which are stored in the HDD152 (or the ROM) of the personal computer PC and define options of animage processing mode GM specified by the image processing controlinformation GI. The terminology ‘file structure’, ‘data structure’, and‘storage area’ used in this embodiment represents the image of a file ordata in the storage state in a storage device.

The image file GF includes JPEG image data GD and application markersegments APP to store attribute information of the JPEG image data GD.The application marker segments APP (IFD) use tags for identifyingrespective pieces of information, and each piece of information may beexpressed by its corresponding tag name. The application marker segmentsAPP shown in FIG. 5 include tags (area) for storing the image processingcontrol information GI, tags (area) for storing the Exif information,and thumbnail image data.

Settings of image quality-relating parameters applied for imageprocessing executed by the personal computer PC or the color printer 20are described in the image processing control information GI. The imagequality-relating parameters include, for example, YCbCr to RGB colorconversion matrix elements and gamma correction values, contrast,saturation, sharpness, lightness, and color balance of the digital stillcamera 12. The image processing control information GI also includesimage processing mode specification information, which is used tospecify an image processing mode GM corresponding to a shooting modeselected at the time of shooting. The image processing mode GM isdefined by multiple image quality-relating parameters, for example,contrast and saturation, as shown in FIG. 7. Each of the imagequality-relating parameters takes different values corresponding todifferent image processing modes GM (shooting modes). A number isallocated to each image processing mode GM. The image processing controlinformation GI specifies a number to identify each image processing modeGM.

The Exif information includes tags for storing user information and tagsfor storing shooting conditions. The user information tags include aMakernote tag arbitrarily usable by the Exif file user (for example, themanufacturer of the DSC). The image processing control information GImay be described in this Makernote tag. Settings of various parametersrelating to shooting conditions including an exposure program and ashutter speed are described in the shooting condition tags as shown inFIG. 6.

C. Image Processing Executed by Personal Computer PC

A series of image processing executed by the personal computer PC isdiscussed below with reference to FIGS. 8 through 11. FIG. 8 is aflowchart showing an image processing routine executed by the imageprocessing apparatus (the personal computer PC) in the embodiment. FIG.9 is a flowchart showing an image quality adjustment routine with theimage processing control information GI executed by the image processingapparatus (the personal computer PC) in the embodiment. FIG. 10 is aflowchart showing an image quality adjustment routine with the Exifinformation executed by the image processing apparatus (the personalcomputer PC) in the embodiment. FIG. 11 shows a table that maps the Exifinformation to the image processing mode GM.

The CPU 150 of the personal computer PC activates an image qualityadjustment program, in response to insertion of the memory card MC intothe card slot 153 or in response to connection of the connector cable CVlinked with the digital still camera 12 to the input output terminal154. The CPU 150 first reads an image file GF from the memory card MCaccording to the user's instruction and temporarily stores the read-outimage file GF into the RAM 151 (step S100).

The CPU 150 determines whether the image file GF includes the imageprocessing control information GI (step S110). When the image processingcontrol information GI is found (detected) in the image file GF (stepS110: Yes), the CPU 150 acquires the image processing controlinformation GI (step S120) and executes a series of image processing(image quality adjustment) with the acquired image processing controlinformation GI (step S130).

The series of image processing with the image processing controlinformation GI is described with reference to FIG. 9. The CPU 150extends the image data GD included in the read-out image file GF andsequentially carries out matrix algebra with a matrix S on the extendedimage data GD, gamma correction with gamma correction values specifiedby the acquired image processing control information GI, and matrixalgebra with a matrix N⁻¹M including a matrix M, so as to implementcolor conversion of YCbCr into wRGB (step S200).

The image file GF processed according to this flowchart stores JPEGimage data, which represent YCbCr data in a compressed form. RGB dataare generally used for image processing executed by the personalcomputer PC and the printer. Extension (decoding) of the JPEG data andthe color conversion of YCbCr data into RGB data are accordinglyrequired. The matrix S is typically used for conversion of YCbCr datainto RGB data in the JFIF format as is known in the art, and is thus notspecifically described here. For linearization of the relation to XYZvalues in the course of color conversion, the gamma correction iscarried out with the gamma correction values specified by the imageprocessing control information GI to attain linearization of the imagedata GD.

The procedure of this embodiment carries out RGB to wRGB colorconversion with the matrix N⁻¹M including the matrix M, which takes intoaccount the color reproduction characteristics of the color printer 20,in addition to the general YCbCr to RGB color conversion with the matrixS. The matrix M has elements specified by the image processing controlinformation GI, and is used to convert the color space from an RGB colorspace (target color space) that defines (specifies) RGB data after thematrix algebra with the matrix S into an XYZ color space that is adevice-dependent color space. When the RGB data after the matrix algebrawith the matrix S have RGB values out of the color range of an sRGBcolor space, a wRGB color space at least partly having a wider colorrange than the sRGB color space is specified as the color space definingthe RGB data after matrix algebra with the matrix S. This arrangementeffectively prevents loss of the RGB values and leads to a subsequentwider wRGB color space (working color space). The matrix N is used toconvert the color space from an RGB color space allowed by the colorprinter 20, for example, a wRGB color space, into an XYZ color space.The matrix N⁻¹M is a composite matrix to attain color conversion fromRGB to XYZ to wRGB.

The CPU 150 acquires the image processing mode GM specified by the imageprocessing control information GI (step S210) and executes image qualityadjustment of the resulting RGB data obtained by the color conversionwith a set of parameters specified by the acquired image processing modeGM (step S220). According to a concrete procedure, the CPU 150 carriesout image quality adjustment with the settings of the imagequality-relating parameters defined by one of the options 1 through 11of the image processing modes GM shown in FIG. 7, which corresponds tothe number specified by the image processing control information GI. Theprocedure of image quality adjustment is explained in detail. The CPU150 analyzes the image data GD in units of pixel and obtains values ofvarious characteristic parameters representing the characteristics ofthe image data GD, for example, image statistics like a minimumluminance, a maximum luminance, and a representative lightness. The CPU150 specifies correction values to cancel or at least reduce differencesbetween reference values, which are preset for the respectivecharacteristic parameters and are stored in the HDD 152, and the imagestatistics obtained by the analysis, and corrects the RGB values of theimage data GD. The correction of the image data GD, for example,corrects a tone curve, which defines a relation between input andoutput, with the specified correction values and substitutes the imagedata GD as an input into the corrected tone curve.

The parameter values specified by the image processing mode GM are usedto change the degree of cancellation or the degree of reduction (theamount of correction) of the difference between the reference value andthe image statistic, while being directly reflected on the amount ofcorrection (the correction value).

For example, when a number ‘2’ is set as the image processing mode GM,the degrees of correction to the reference values are set as slightlysofter (slightly weaker) for contrast, slightly brighter (slightlystronger) for lightness, standard for color balance, slightly lower(slightly weaker) for saturation, and slightly weaker for sharpness. Theflesh color is set as the stored color, so that flesh color data (RGBvalues) stored in advance in the HDD 152 are used for the imageprocessing. The noise reduction is set OFF. The image quality adjustmentis carried out in the image processing mode corresponding to eachshooting scene. When the selected shooting scene is twilight scene, forexample, red color seepage is not removed. When the selected shootingscene is nightscape, in another example, the image data is not correctedto be brighter by lightness correction. Namely this arrangement ensuresexecution of image quality adjustment reflecting the intention of thephotographer.

The image processing control information GI may include individuallysettable, image quality-relating parameters, such as lightness andcontrast, other than a set of image quality-relating parameters forspecifying the image processing mode GM. Such individually settableparameters are not specifically described here.

The CPU 150 carries out color conversion to convert the resulting imagedata (RGB data) after the image quality adjustment into CMYK data (stepS230), and returns to the image processing routine shown in FIG. 8. Thisprocess converts the color system of the image data to the CMYK colorsystem adopted by the color printer 20 for execution of printing. Aconcrete procedure refers to a lookup table, which maps the RGB colorsystem to the CMYK color system and is stored in the HDD 152 (ROM).

When the series of image processing discussed above is concluded and theprogram returns to the image processing routine shown in FIG. 8, the CPU150 carries out a print output process of the resulting image data (stepS140) and then exits from this processing routine. In the print outputprocess, the CPU 150 successively executes a halftoning process and aresolution conversion process and transmits the processed data as rasterdata to the control circuit 50 of the color printer 20.

When the image processing control information GI is not detected in theimage file GF (step S110: No), the CPU 150 determines whether the Exifinformation is detected in the image file GF (step S150). When the Exifinformation is not retrieved in the image file GF (step S150: No), theCPU 150 carries out a series of standard image processing with presetimage processing conditions, which do not depend upon the selectedshooting mode (step S180), outputs the processed image data (step S140),and exits from this processing routine. The standard image processingmay execute image quality adjustment with reference values.

When the Exif information is retrieved in the image file GF (step S150:Yes), on the other hand, the CPU 150 acquires the Exif information (stepS160) and carries out a series of image processing (image qualityadjustment) with the acquired Exif information (step S170).

The series of image processing with the Exif information is discussedbelow with reference to FIG. 10. The CPU 150 extends the image data GDincluded in the read-out image file GF and carries out matrix algebrawith the matrix S on the extended image data GD, so as to attain YCbCrto RGB color conversion (step S300). The CPU 150 subsequently determineswhether a selected shooting mode, for example, portrait, twilight scene,or nightscape, is described in the Exif information (step S310).

When the shooting mode is detected in the Exif information (step S310:Yes), the CPU 150 selects and acquires the image processing mode GMcorresponding to the shooting mode described in the Exif information(step S320) and executes image quality adjustment in the acquired imageprocessing mode GM (step S330). In general, the number of shooting modesdescribed as the Exif information is less than the number of imageprocessing modes GM. No problem accordingly arises in the mapping of theExif information to the image processing mode GM. When the number ofshooting modes described as the Exif information exceeds the number ofimage processing modes GM, the number of image processing modes GM issimply to be increased. The image quality adjustment in the imageprocessing mode GM follows the procedure of image processing with theimage processing control information GI discussed above.

When the shooting mode is not detected in the Exif information (stepS310: No), on the other hand, the CPU 150 selects and acquires the imageprocessing mode GM based on other shooting conditions described in theExif information (step S340) and executes image quality adjustment inthe acquired image processing mode GM (step S330). A table shown in FIG.11 is, for example, applicable for the mapping of the shootingconditions to the image processing mode GM. The shooting conditions usedin this embodiment are a combination of an exposure program for settingthe priority to either of the shooting parameters, the exposure or theshutter speed, an aperture value (F number) representing the setting oflight exposure to the CCD, a shutter speed representing the setting ofan exposure time to the CCD, a subject distance range, an ISO speed raterepresenting the sensitizing quantity, and a flash operating state likeprohibited emission or forcible emission. These shooting conditions areonly illustrative and not restrictive in any sense. Other shootingconditions including white balance, gain control, contrast, saturation,and sharpness of shooting, a digital zoom magnification, an exposuretime, a light source, and a subject area may adequately be added to theabove combination or used in different combinations.

The CPU 150 carries out color conversion to convert the resulting imagedata (RGB data) after the image quality adjustment into CMYK data (stepS350), and returns to the image processing routine shown in FIG. 8. Thisprocess converts the color system of the image data to the CMYK colorsystem adopted by the color printer 20 for execution of printing. Aconcrete procedure refers to a lookup table, which maps the RGB colorsystem to the CMYK color system and is stored in the HDD 152 (ROM).

When the series of image processing discussed above is concluded and theprogram returns to the image processing routine shown in FIG. 8, the CPU150 carries out the print output process of the resulting image data(step S140) and then exits from this processing routine. In the printoutput process, the CPU 150 successively executes a halftoning processand a resolution conversion process and transmits the processed data asraster data to the control circuit 50 of the color printer 20.

As described above, when the image processing control information GIincludes the information for specifying the image processing mode GM,the personal computer PC functioning as the image processing apparatusof the embodiment executes image processing (image quality adjustment)in the image processing mode GM selected according to themode-specifying information. This arrangement ensures execution of imagequality adjustment corresponding to the shooting mode selected at thetime of shooting, that is, image processing to give the photographer'sdesired output image.

When the information for specifying the image processing mode GM is notincluded in the image processing control information GI, the procedureexecutes image quality adjustment in the selected image processing modeGM corresponding to the shooting mode described as the Exif information.This arrangement ensures execution of image quality adjustmentcorresponding to the shooting mode selected at the time of shooting,that is, image processing that reflects the intention of thephotographer.

When the shooting mode is not described as the Exif information, theprocedure uses the Exif information other than the shooting mode toselect the image processing mode GM corresponding to the shooting modeat the time of shooting and executes image quality adjustment in theselected image processing mode GM. As long as the Exif information isincluded in the image file GF, this arrangement ensures execution ofimage processing corresponding to the shooting scene at the time ofshooting, that is, the image quality adjustment reflecting thephotographer's intention.

The personal computer PC functioning as the image processing apparatusof the embodiment selectively executes an adequate series of imageprocessing among the three options discussed above according to theimage file GF. This arrangement ensures execution of the most adequateimage quality adjustment well reflecting the photographer's intentionand enables a greater number of image files GF to be subjected to thedesired image quality adjustment.

The procedure of the above embodiment utilizes either the informationfor specifying the image processing mode GM or the shooting modedescribed as the Exif information to specify the image processing modeGM, based on whether the information for specifying the image processingmode GM is included in the image processing control information GI. Onepossible modification may utilize either the information for specifyingthe image processing mode GM or the shooting mode described as the Exifinformation to specify the image processing mode GM, in response to theuser's selection. This modified arrangement ensures execution of imageprocessing that adequately reflects the user's intention.

The procedure of the above embodiment adopts the image processing modeGM corresponding to the image processing control information GI. Onepossible modification provides an image processing mode GM′corresponding to the shooting mode, in addition to the image processingmode GM corresponding to the image processing control information GI,and executes image processing, in response to the user's selection,either in the image processing mode GM corresponding to the informationfor specifying the image processing mode GM or in the image processingmode GM′ corresponding to the shooting mode described as the Exifinformation. This arrangement ensures execution of adequate imageprocessing that well reflects the user's intention.

When the image processing control information GI does not include theinformation for specifying the image processing mode GM, the procedureexecutes image quality adjustment in the image processing mode GM, whichis selected corresponding to the shooting mode described as the Exifinformation. This arrangement ensures image quality adjustmentcorresponding to the selected shooting mode, that is, image processingthat well reflects the photographer's intention.

In the structure of the above embodiment, the personal computer PCfunctioning as the image processing apparatus executes the whole seriesof image processing and outputs the processed image data to the colorprinter 20. In one modified structure, the color printer 20 may execute,without the assistant of the personal computer PC, all or part of theimage processing and create a dot pattern according to the processedimage data GD on a printing medium. The computer may assist theexecution. In such modification, the color printer 20 has the imageprocessing functions discussed above with reference to FIGS. 8 through11. The image file GF generated by the digital still camera 12 isdirectly transmitted to the color printer 20 via the cable or via thememory card MC. The image processing program is automatically activatedin response to detection of insertion of the memory card MC or inresponse to detection of attachment of the cable, to automaticallyperform input of the image file GF, retrieval of the image processingcontrol information GI and the Exif information, conversion of the imagedata GD, and image quality adjustment. Another possible modificationprovides an auto image quality adjustment button on the operation panelof the color printer 20. The auto image quality adjustment processdiscussed in the above embodiment may be executed only in the case ofselection of an auto image quality adjustment mode through the operationof the auto image quality adjustment button.

In the structure of the above embodiment, the color printer 20 is usedas the output device. The output device may be a display device, such asa CRT, an LCD, or a projector. In such cases, the display devicefunctioning as the output device executes an image processing program(display driver) to implement the image processing described above withreference to FIGS. 8 through 11. When the CRT or the like functions as adisplay device of the computer, the computer executes the imageprocessing program. Here the eventually output image data has the RGBcolor space, instead of the CMYK color space.

The resulting display on the display device, such as the CRT, reflectsthe image processing control information GI, as the resulting print bythe color printer 20 reflects the information obtained at the time ofgenerating the image data. This arrangement ensures accurate display ofthe image data GD generated by the digital still camera 12.

The embodiment regards the image file complying with the Exif fileformat as a concrete example of the image file GF. The image processingapparatus of the invention is, however, not restricted to processing ofthe image files of this format, but is also applicable to processing ofthe image files GF complying with the JFIF file format and thosecomplying with the TIFF file format. The image file processible by theimage processing apparatus of the invention is required to include theimage data GD and at least either of the image processing controlinformation GI and the Exif information related to the image data GD.

In the embodiment discussed above, the personal computer PC and thecolor printer 20 are only illustrative and are not restricted to thestructure discussed above. The personal computer PC and the colorprinter 20 are required to have at least the functions of retrieving theimage processing control information GI or the Exif information in theimage file GF, which may store both of the image processing controlinformation GI and the Exif information, selecting the image processingmode GM based on the retrieved information, carrying out auto imagequality adjustment in the selected image processing mode GM, andoutputting (printing) the processed image.

In the structure of the above embodiment, the image data GD and theimage processing control information GI are included in the identicalimage file GF. The image data GD and the image processing controlinformation GI may not be stored in an identical file. The requirementis that the image data GD is related to the image processing controlinformation GI. One possible modification generates mapping data torelate the image data GD to the image processing control information GI,stores one or multiple image data GD and the image processing controlinformation GI in separate files, and refers to the image processingcontrol information GI related to the image data GD at the time ofprocessing the image data GD. In this modified structure, the image datais inseparably integrated with the image processing control informationGI in the course of image processing with the image processing controlinformation GI. This gives the substantially equivalent functions tothose attained by storage in the identical file. The technique is alsoapplicable to video files stored in optical disk media, such as CD-ROMs,CD-Rs, DVD-ROMs, and DVD-RAMs.

The image processing apparatus and the image processing method of theinvention are described above with reference to some embodiments. Theseembodiments are to be considered in all aspects as illustrative and notrestrictive. There may be many modifications, changes, and alterationswithout departing from the scope or spirit of the main characteristicsof the present invention. All changes within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

1. An image processing method that makes image data, which includesshooting information obtained at a time of shooting, subjected to aseries of image processing, said image processing method comprising:retrieving image processing control information that is related to theimage data and is used to specify an image processing condition; in thecase of failed retrieval of the image processing control information,selecting an image processing condition, which is suitable for ashooting condition at the time of shooting; and executing image qualityadjustment of the image data with the selected image processingcondition.
 2. An image processing method in accordance with claim 1,wherein said selecting the image processing condition, in the case ofsuccessful retrieval of the image processing control information, isimplemented with selecting an image processing condition specified bythe retrieved image processing control information from said memorydevice.
 3. An image processing method in accordance with claim 1,wherein said selecting the image processing condition, when the shootinginformation includes preset information of shooting scene at the time ofshooting, is implemented with selecting the image processing condition,based on the preset information of shooting scene.
 4. An imageprocessing method in accordance with claim 1, wherein said selecting theimage processing condition is implementing with at least information onsettings of exposure program, aperture, shutter speed, subject distancerange, ISO speed rate, and flash included in the shooting information.5. An image processing method in accordance with claim 3, wherein saidselecting the image processing condition, when the shooting informationdoes not include the preset information of shooting scene at the time ofshooting, is implemented with at least information on settings ofexposure program, aperture, shutter speed, subject distance range, ISOspeed rate, and flash included in the shooting information.
 6. An imageprocessing method in accordance with any one of claims 1 through 5,wherein the image processing condition is a combination of values ofmultiple image quality-relating parameters, which are set in advance foreach shooting scene.
 7. An image processing apparatus that makes imagedata, which includes shooting information obtained at a time ofshooting, subjected to a series of image processing, said imageprocessing apparatus comprising: a memory module that stores multipledifferent image processing conditions set for the image data; aselection module that, in the case of failed retrieval of imageprocessing control information that is related to the image data and isused to specify an image processing condition, selects an imageprocessing condition, which is suitable for a shooting condition at thetime of shooting, based on the shooting information from said memorymodule; and an image quality adjustment module that executes imagequality adjustment of the image data with the selected image processingcondition.
 8. A computer program product storing an image processingprogram that causes a computer to make image data, which includesshooting information obtained at a time of shooting, subjected to aseries of image processing, said image processing program comprising: aprogram command that retrieves image processing control information thatis related to the image data and is used to specify an image processingcondition; a program command that, in the case of failed retrieval ofthe image processing control information, selects an image processingcondition, which is suitable for a shooting condition at the time ofshooting, based on the shooting information among multiple differentimage processing conditions set in advance for the image data; and aprogram command that executes image quality adjustment of the image datawith the selected image processing condition.